The present invention relates to work lights used to illuminate task or work areas.
Conventionally, fluorescent or incandescent work lights are used to provide light in work areas. Such lights need to be relatively compact and portable. Work lights conventionally include a handle for gripping the light and a fluorescent or incandescent lamp for providing light to an area. The lamp may be at least partially covered by a transparent cover. The work light may include a cord and plug for connection to an electrical outlet. Alternatively, the work light may be battery operated.
Incandescent lamps have a thin filament which is energized to emit light when the work light is supplied with electrical current. A problem with work lights having incandescent lamps is that the filament in these light bulbs is fragile and may break relatively easily. The life of an incandescent bulb is determined by the length of time the filament stays intact as, once the filament breaks, the light bulb is no longer usable and must be replaced. A further problem with incandescent lamps is that they emit a substantial amount of heat. As batteries run down in incandescent work lights, the intensity of the light also tends to decrease.
Fluorescent work lights are preferred to those having incandescent light bulbs or lamps. Fluorescent lamps have a longer life than incandescent lamps. Fluorescent lamps do not have a fragile filament. Fluorescent lamps are constructed with a thin glass tube molded to a desired shape. Air is evacuated from the glass tube which is thereafter filled with a gas which forms a plasma in the presence of an electric field. Electrons from the plasma are absorbed by and excite a phosphor which coats the tube. The excited phosphor fluoresces or gives off visible light. Fluorescent lamps have a pair of leads at one or both ends which are inserted into a socket located in the handle or end cap of the work light. A problem with fluorescent lamps is that the glass of the tube may be thin and thus fragile. Other problems with fluorescent work lights are that the leads may tarnish or become loose in the socket, thereby breaking the electrical connection. Another problem with fluorescent work lights is that these types of lights require a relatively significant amount of voltage to operate. If battery operated, several batteries may be required to properly energize the lamp of the fluorescent work light making the work light heavy and cumbersome. Due to the amount of power required by the lights, the batteries must be replaced relatively often to maintain operation of the light.
LED lamps are well known and generally emit colored light such as red, green, or blue. When put together in a cluster, the light emitted appears as white light. LED lamps have conventionally not produced a sufficient amount of light so that they could be used in work lights and the like. However, recently LEDs which produce white light have been used in overhead reading lights on airplanes, in side view mirrors on vehicles, and in flashlights. These types of flashlights may be smaller such as a penlight which is about the size of an ink pen. An advantage of LEDs is that they have a long life.
It is desired to provide a work light which utilizes LED lamps as the source of light to provide a work light having a long life, requiring low power, and producing low heat while still supplying a bright light.